Stator blows with annoying regularity? then read this

[treedragon]

I happened to mention at work how there was at least one case I had read where a stator fried itself with almost predictable monotony..........

"I know what causes that, you need to change the flywheel." was the comment.

He had a case years ago on an XZ550 with the same symptoms.  It turns out the polarity in a couple of the magnets was back to front instead of NSNSNS etc it was like NSNNSSNS, loaded up the windings something terrible. Changing the flywheel solved problem.
He quoted some other cases on different bikes with essentially the same problem.

Hope it helps someone.

[sunburnedaz]

Interesting I wonder if one could test this with a small neodymim magnet marked with an N and S. Then as you moved it around the flywheel it would point SNSNSN and if it was bad it would be SNSSNNSN

[treedragon]

Yup that's how they tested, violent reaction when it came to the double.

[Brian Moffet]

If true, that would explain the randomness of the failures.

Hmm, who do we know that could test this out...  I think I heard of someone who went through stators really fast....  He might even have a compass or something  ;D

Brian

[inanecathode]

He's too busy star gazing :P

[h2olawyer]

I've changed the R/R (again) and have more than the usual miles on this stator - still going strong.  Or at least it was when I parked it last Fall.

I have wondered about the flywheel in the past - but more as a source of vibration than magnet issues.  If the current stator fries soon (mileage-wise) I'll try a swap.

Thanks for the info!

Yes, I have been spending lots of time both looking skyward and now getting ready to build my next telescope.

H₂O

[YellowJacket!]

Could this possibly be the solution to one of the longest standing mysteries of the Vision?  Stay tuned folks...I'm sure this is going to get interesting!

David

[akvision]

DEEP!  A quickening may be near.

[Lucky]

actually, the original Yamaha manual mentions weak magnets as a possable diagnostic problem...

[Re-Vision]

I finally found a small compass and checked out the magnets on a parts bike I picked up a few months ago. I know its had a replacement stator because it has a Ricky stator decal on the rear fender and the stator looks to be in excellent condition, anyway, the magnets were NSNSNS for all six magnets for whatever thats worth.   BDC

[jasonm.]

I thought I mentioned to H2O WAAAAAY back. If you have replaced all parts and are NOT running damn driving lights. That the issue  MAY BE the flywheel or wiring harness.  PS. others have discussed this "off line". Note: most 83's have less stator issues. The flywheel may be different.  I have noticed one manufacturing difference of the flywheel from my 5 XZ's that I won't go into. I.E- Treedragon has a good point.

[akvision]

So, the word is...  If there is a DOUBLE you are in TROUBLE.

good= NSNSNS or SNSNSN :) :)

BAD>> NNSSNS  of any combination of two norths of souths side by side.  >:( >:(

Do we all concur?? :police:

[Tiger]

I thought I mentioned to H2O WAAAAAY back.

You did...after we talked about in Syracuse last year... ;)

So, the word is...  If there is a DOUBLE you are in TROUBLE.

good= NSNSNS or SNSNSN :) :)

BAD>> NNSSNS  of any combination of two norths of souths side by side.  >:( >:(

Do we all concur?? :police:

:) Yes...

[jasonm.]

Thanks Tiger...my memory sucks....got that Scotch?  I need a drink

[h2olawyer]

I did do a flywheel change in one of the many stator replacements.  Still say it was a FUBAR new OEM type R/R that I trusted.  The next R/R I installed gave me 1500 miles before that R/R fried.  Then I swapped back to the previous R/R & got the typical 1000 additional miles out of the stator.  (2500 total on that one).  I have another R/R (from RM Stator) in it now and got close to 1000 miles on the whole setup before the riding season ended.  I'll have to wait for it to warm up around here (global warming my @$$) and riding season to begin again so I can see if I get more miles again.

H₂O

[67GTO]

Yes, keep track of your mps for us :)  (sorry I could'nt help it)

[Brian Moffet]

(global warming my @$$)

I don't think global warming is localized to just your @$$ :-)  Though with the seat warmers in my car on full, it can feel like that...

[jasonm.]

H2o, I feel your pain. But you are swapping parts...but this is not how to trouble shoot things. Would you take your car to a "mechanic" who swapped parts before doing the proper diagnostics? I suspect you are not an electronics tech like me. You need a good DVOM and knowledge on how to test stuff. YOU NEED TO FIND THE CAUSE of the stators failing.And have all your replacement stators been Yamaha OEM or some crap China stuff?  I believe I have stated most of the above...before. YOU SHOULD HAVE NO EXTRA ELECTRICAL LOADS ON THE BIKE. No driving lights, NOTHING. Then start from scratch. Otherwise you are just sticking your "head in the sand".   Also Treedragon...I don't know the watts of those 2 headlights. But you also could be getting to cooking stator time soon. These bikes have very little spare wattage to give.

[inanecathode]

H2o, I feel your pain. But you are swapping parts...but this is not how to trouble shoot things. Would you take your car to a "mechanic" who swapped parts before doing the proper diagnostics? I suspect you are not an electronics tech like me. You need a good DVOM and knowledge on how to test stuff. YOU NEED TO FIND THE CAUSE of the stators failing.And have all your replacement stators been Yamaha OEM or some crap China stuff?  I believe I have stated most of the above...before. YOU SHOULD HAVE NO EXTRA ELECTRICAL LOADS ON THE BIKE. No driving lights, NOTHING. Then start from scratch. Otherwise you are just sticking your "head in the sand".   Also Treedragon...I don't know the watts of those 2 headlights. But you also could be getting to cooking stator time soon. These bikes have very little spare wattage to give.

Here's the thing though:

Its a shunting regulator, and a permanent magnet charging system. The stator is at full load, 100% of the time. The regulator demands 100% power at all times. The waste heat is coming out of the regulator, not the stator. The stator supplies the voltage, not limits it. The permanent magnet system can't 'overload'. It's already at full field, all the time (permanent magnet, right?). The only thing you accomplish by removing all electrical load is in fact putting MORE heat out through the regulator. Presumably, the regulator can handle the heat. Using every single watt you can possibly get out of the stator will do nothing, in fact all that electrical energy that would otherwise be converted right into heat energy by the regulator is shifted to other purposes, lights, heated grips, whatever. Here's what will happen when you overload the vision system; The battery drains and everything shuts off (actually, tci dies at about 10 volts). I could connect an arc welder to the battery when the bike is running and all that will happen is the regulator will tap out (every ounce the stator is giving goes to the device, no more than its already outputting) the battery will discharge because the system drops below 14.5 volts, and stuff just quits.

What you're saying applies to active rotor alternator generators. If i keep putting more and more and more crap onto the electrical circuit on, say, my chevy cavalier (was going to say the rd400, but i think thats actually at full field all the time anyway). The regulator demands more and more and more current, so it increases field voltage more and more and more until it's full fielded. Alternators don't take full field very long (unless its a heavy duty model) and eventually that extra magnetism cutting the stator windings WILL overheat the thing. The difference is the vision stator is ALREADY full fielded, an alternator is not. When i connect my arc welder to my cavalier, sure it will discharge the system because theres no way im putting out that much power, but it will blow up the alternator at some point because its not designed to go full field very long, maybe once at startup when the a/c is on.

On and on we go into the age old angry electron debate, but long story short:
Vision stator is full fielded 100% of the time
Regulator demands full voltage 100% of the time
Extra electrical 'loads' actually don't 'load' anything, then unload the regulator if anything
If you unplug the R/R from the stator, nothing happens. Current doesnt exist with no circuit (heading off that argument ahead of time)

I havent put much thought into the wrong polarity magnet idea, doesnt make sense to me really but a whole lot of things dont, i've always had a pet theory that an out of balance rotor will make unfriendly vibes (undetectable frequency) and shake the windings enough to eventually short. Really, though, i could see how an out of balance magnetic field could do the same thing. The stator armature is steel, you know, at high rpms i could see how it flexes minutely with the different polarity fields. I could also see how a double strength polarity could flex it much more, and at higher rpms i could see a resonance happening...


Edit: Actually, now that i think of it, they do make welder kits that run off the serpentine belt. Really high quality high heat alternator, but yes, they too can run at full field, but they're designed to do it. Never thought of a need to run a bead if i'm out and about, i guess if you're offroading though :)

[jasonm.]

...inanecathode...You are oversimplifying the system and how it works.   Yes the system is always working and excited. BUT NOT AT MAX power.Ours does not get near max till 3000rpm or so. Thus not getting your "max  AC voltage" till then.  And that's converted to about 250w 14vdc in our system. ALL A RESULT OF RPM AND AVAILABLE GERERATED FLUX. FLUX IS ALWAYS LOWER AT LOWER RPM. And that's where the R/R comes in. As we know, to change AC to DC and dump what's not needed. A.K.A. TO take what's available and change it into what we need. SAY IT AGAIN,  "max is not available all the time." Jeeeeezzzzz basic law of generator design...More rpm = more available power.If you exceed the system's available output by excessive draw, you are going to have problems. Look in the back of the service manual. PS> I have built generator/alternators . All generate electricity and the byproduct is ALWAYS heat.heat. This just happens to be one design with less than stellar parts and ability to draw the heat out.If you can't get 7-10k out of a stator...you surely have something very wrong But still, I am on my original stator close to 33kmiles. Maybe I'm the luckiest SOB out here?